In this video you're gonna learn all the different types of combinations of
naming ionic compounds and molecular, also known as covalent compounds. Alright,
let's do this!
Hello hello Melissa Maribel here and I help students like you
understand what you just learned in class. So you stress less and you graduate
faster. All right guys, this is a very VERY important lesson today, because you
will be naming compounds until the end of the semester and if you decide to
continue with chemistry, you'll be naming compounds forever.
So if you need to pause replay or write anything down, please please do so. I will
be letting you know what you need to understand versus what you need to
memorize. Okay, here is a simple strategy that has helped my students remember how
to name compounds correctly. The strategy is to identify the type of compound from
the very beginning. Whether it's ionic or molecular. Molecular refers to covalent
compounds. An ionic compound consists of one metal and one nonmetal. A covalent
compound consists of two nonmetals. Looking at your periodic table the
highlighted portion shows you all the different types of nonmetals. Everything
there after then is a metal. We'll start with the different types of naming
for ionic compounds. The first one, ionic compounds without a transition metal.
Aluminum Oxide shows you the name of the metal, our aluminum, and oxygen, or our
nonmetal, ending in "ide." Looking at the periodic table we need to identify our
charges, so if you have to pause the video and write these down, these are the
charges that you need to have memorized. For ionic compounds you will always have
to balance out your charges. For this example aluminum oxide, let's identify
the charges for aluminum and oxygen. Aluminum's charge is a
3+ charge and oxygen has a 2- charge. Aluminum had that 3+ charge
and oxygen had the 2-. Let's balance these charges out by multiplying our
aluminum or, really, placing a subscript of 2, that 2 then multiplies with our
3+ charge and it becomes a 6+ charge. We want these charges to be the
exact same. So I'll also then place a 3 subscript, that would then turn this 2-
to a 6- charge and our charges are balanced. Another way of looking at
this is to really "lasso," I've heard that term before, our charges where our
aluminum gets that 2 and oxygen then gets the 3. They get the opposite charges
of each other just so they can make the same exact charge. They would then cancel
out the charges and be neutral. And our final balanced compound is aluminum
oxide having that subscript of 2 and 3. The second one is ionic compounds with a
transition metal. This consists of the name of our transition metal, a Roman
numeral in parentheses, and a nonmetal ending in "ide." Our transition metal is
iron and our Roman numeral is 3. Your Roman numeral actually tells you the
charge of your transition metal. A lot of times transition metals have different
types of charges. Iron sometimes has a 2+ or a 3+ charge, so our Roman
numeral actually tells us the charge of what iron is, within this compound. Your
nonmetal is the oxygen and once again that ends in "ide." So we need to balance
out our charges. Your iron as we saw was a 3+ charge, your oxygen was a
2- charge. Balancing out these charges we'll place a 2 subscript for our iron
and a 3 subscript for the oxygen. We now have these sixes canceling out, which is
what we wanted, and your final compound is Fe2O3.
Polyatomic atoms just means that there are two or more elements within that
atom. Know these polyatomic atoms. Write some flashcards.
I will also place a link in the description box of more polyatomic atoms
that you should also know. Moving on to ionic compounds with a polyatomic atom.
They consist of the name of our metal and our polyatomic atom. Notice that you
do not have your nonmetal ending in "ide." A lot of times polyatomic atoms end in
"ate" or "ite" with the exception of hydroxide and cyanide. We have calcium
phosphate. Calcium is the name of our metal and phosphate is our type of
polyatomic atom. Polyatomic atoms do have specific charges, so that is once
again something you do have to know. Calcium has a 2+ charge, phosphate
has a 3- charge. Our phosphate started off with having four oxygen. So
to balance out our charges we need to place this in parentheses to isolate
that phosphate group.
Doing so, we'll place our three with our calcium, that'll once again give us
a 6+ charge. We'll place our 2 on the outside of parentheses. Polyatomic
atoms tend to have parentheses whenever we place a subscript. These are now
balanced and your final compound is calcium phosphate. This is how it's
properly balanced. Our last ionic compound mixes transition metals and
polyatomic atoms. It consists of the name of the transition metal, a Roman numeral,
and the polyatomic atom. Here we'll see Copper (II), once again that (II) tells us the charge
of copper, which is our transition metal, and our polyatomic atom of nitrate.
Nitrate is NO3 and has a -1 charge. We saw that copper had that
2+ charge so all we need to do is just have a 2 for our nitrate since copper is
already 2. Balancing out our charges we'll place this in parentheses and place our
2 subscript outside and we'll have these twos cancel. Your final compound is
copper nitrate with a 2 subscript only on the nitrate. Let's start with
going backwards now. So instead of having the compound name
we're given the formula and asked to actually write the name of the compound.
FeBr2, Fe is known as iron and Br is known as bromine. Iron is a type of
transition metal, bromine is a nonmetal. So our nonmetal will end in "ide" and we
know that a transition metal will have a Roman numeral. To figure out what your
Roman numeral is, let's go back to the overall charges. So bromine is a type of
halogen, just meaning that it has a -1 charge. So since this had
a -1 charge, Fe or iron, must have had a 2+ charge. Another way
of identifying this, is if we were to go backwards, this 2 would go back on to
the iron, since bromine needed 2 to balance out the charges altogether. So
we'll have iron (II) bromide. Let's try another example like that.
Cu3(PO4)2. Cu is known as copper. It is a type of transition metal
so we have to have a Roman numeral. PO4 is a type of polyatomic atom.
We had to know that polyatomic atoms charge was a 3- because this then
allows us to figure out that copper had a 2+ charge. Another way of
looking at this is, this 2 goes back to the previous element. So that 2 belongs
to the copper and this 3 then belongs to our phosphate group. That's a trick that
you can use whenever you're using your formula and you're trying to go back to
the actual name of the compound. So our name of our compound would then be
copper (II) phosphate. Those are all the different types of combinations for
ionic compounds. Moving on to covalent or molecular compounds. Something that we
have to know are the prefixes. Know 1 through 10 because you do not have to
balance any of the charges, I repeat for covalent compounds do not balance
charges. Covalent compounds consists of two nonmetals as we mentioned before.
The setup will be that there is a prefix plus the name of your nonmetal, next
another prefix plus the name of your nonmetal ending in "ide."
Diphosphorus Pentoxide. You will also hear this as Penta oxide. The most common form is
pentoxide. Our subscript is that "Di" and the "Pent." "Di" meaning two and "Pent"
meaning five. Once again we do not have to balance any charges. All you have to
notice is the "Di" means two, so there are two phosphorus. The "Pent" means five so
there is five oxygen. That's it, you're done no balancing charges. Your prefixes
literally tell you how much of that element there is. We have N3O6. We'll look
at the different subscripts and figure out what prefix they need. So our three
meaning "tri" and six means "hexa." So we'll put "tri"
and then the name of our nonmetal which was nitrogen, then we'll put "hexa" and the
name of our other nonmetal ending in "ide." So we have Trinitrogen hexaoxide. Now I
hope you don't plan on leaving here without practicing what you just learned.
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